"Sciama presents lucid explanations of cosmology and the dark matter problem in general, worth reading for their clear distillations of complicated observational facts....an excellent survey of the subject of cosmic and galactic ionization, at a level of detail not found in cosmology texts." Science
"...The book is the epitome of clarity, and it will also make students think." David Hughes, New Scientist
"Although Sciama's neutrino scenario has been circulating in the cosmological community for several years, it was divided among many separate papers and until now was not all available in one place. Furthermore, for the nonspecialist, the book introduces and explains modern cosmology and the nature of dark matter problems themselves rather well. It is definitely a useful addition to the cosmological literature." David N. Schramm, Physics Today
The author's theory, though speculative, explains a number of rather different puzzling phenomena, in showing how the need to introduce dark matter in the universe has developed, mostly in the form of neutrinos created in the hot big bang and surviving to the present day.